Pioneer and Plextor DVD burning problem.

Ok, I don't know the models off hand and I doubt that really matters because of this unique problem.
I have a Pioneer 4x DVD burner and a Plexter 4x DVD-R (8x DVD+R) burner.
I take my Imation 4.7GB (4.4 or so roughly) and add 3.7GB of data to Roxio's DVD burning software OR the software that came with the Pioneer burner.
So I want to burn roughly 12,000 files to a DVD. I copy all files local to my hard drive off my network. Using the software (tried updating and using a non-updated version) I place all my files on the DVD and begin burning. It burns for 30 minutes at 1-2x due to the amount of files I assume. After about 30 minutes the DVD finishes successfully. The entire file directory is copied down and there, but no files. 180MB EVERY time I burn a DVD. Now, randomly I can get 98% of the files to burn, but somewhere along the way a small directory of 30 files or so won't burn yet everything else is fine.

Anyone know of any odd problems like this? Now this happens with both burners, on 3 different test machines.
I'm used a 2.4GHz Dell system, a 933MHz Abit ATA100 motherboard to do this. Same results, so I know it's not the computer hardware causing the problem.

I get 180MB each time burned to the DVD-R. I've tried DVD+R with the same results. I'm using Imation and some other brand of DVDs that came with the burners.

Now, I haven't updated the firmware on either drive, but because it happened to both drives with identical results, I wasn't in a huge hurry to do that.

I could try creating an ISO image, but i'm trying to avoid that due to the extra work involved and I'm not going to be the one having to deal with extracting an ISO to find 2 files on a completely full DVD.

Any help is appreciated.

Thanks,
Riser